Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed.
On the diesel Passat, the TDI badge stands for Turbocharged Direct Injection, which isn't really all that helpful as the gasoline-powered Passat is also turbocharged and also uses direct injection. Volkswagen attempts to clear this up by calling this Passat the Passat TDI Clean Diesel.
The newer TDI engine on European Audi Q7 for 2010 switched over to a simpler 2 chain system. Since it's a completely different engine, it's not possible to swap your chain drive. Some older gasoline V6, V8 Audi and VR6 VW engines used a similar chain system and needed chain service as low as 100,000 miles.ome of the technology on the CATA 3.0L TDI engine is common rail fuel injection which uses extremely rapid piezoelectric (like the vibrating sonicare toothbrush head) injections of fuel at about 29,000 psi! To compare, the average gasoline engine injects fuel at about 60 psi. The turbo is a VNT variable nozzle turbo.